Billie Eilish Makes Acting Debut in Swarm, in Creepy Role Inspired by Real Cult-Leader

Warning: spoilers for Swarm ahead.

Billie Eilish just teased something major, and it's not a new album — it's her acting debut. Surprise! Billie is set to guest star in Donald Glover's new Prime Video series Swarm.

Swarm, which also stars Chloe Bailey as Dre's sister Marissa, Damson Idris, Rickey Thompson, Kiersey Clemons, and Paris Jackson, made its streaming premiere on Prime Video on March 17. Swarm is set between 2016 and 2018 and stars Dominique Fishback as the twisted heroine Dre, an obsessive fan of the world's biggest pop star whose fandom takes a dark turn, sending her on an unexpected cross-country journey. 

Swarm has already received lots of buzz for its bloody trailer and the intentional similarities to Beyoncé and her fandom the BeyHive. (Fun fact: Malia Obama is credited as a writer on the series, after discreetly joining the writers room back in March 2022.)

Now, who Billie Eilish plays in Swarm is where it gets even more fun. Her mysterious character, named Eva, is the leader of an all-female cult.

In a teaser the musician posted to Instagram on March 16, we see a blonde Billie — aka Eva — opposite Dominique as Dre, asking her what she sees and looking very pleased when Dre admits that she hurt someone. "Very good," Billie's character says in a low, haunting voice. Um, I have chills? In the official teaser trailer for the series, we get a little more of Billie in her cult leader role, once again playing opposite Dominique's Dre. Her casting comes as a surprise, given that she wasn't originally announced as a player attached to the project.

Co-showrunner Janine Nabers told Rolling Stone that Billie's involvement in the show is all thanks to revered casting director Carmen Cuba. “We were looking to cast the episode and she suggested Billie, and I said, ‘Does she act?’ And she said, ‘Yeah.’ And I said, ‘What has she been in?’ And she said, ‘Nothing,'" Nabers recounted. “But what’s so incredible about this process is that you have a lot of people that work on the show that are multi-hyphenate and people who have so many different passions. We gravitate toward people who are juggling multiple hats.” Nabers went on to explain that Billie's character Eva, who leads a cult under the guise of a “women's empowerment group," was inspired by NXIVM cult leader Keith Raniere. 

Perhaps the team behind Swarm wanted to keep Billie's involvement a secret for the ultimate impact, which they have definitely achieved. Since the show's debut on March 17, fans have been losing it over Billie's performance in episode 4 of Swarm, which is titled “Running Scared.” (So many fancams were born!) Critics are also praising Billie's impressive acting chops, with Rolling Stone tweeting: “A star is born.”

“[Billie is] so respectful of the craft. She came in with ideas, wanting to talk about it, being game to rehearse,” series lead Dominique Fishback told the outlet. “I think she’s wonderful. I’m such a fan of her as a person due to what I experienced with her on set.”

The feeling seems to be mutual — in a heartfelt Instagram post over the weekend, Billie shared behind-the-scenes shots from her time on the set of Swarm, along with photos of her and Dominique, whom she called her “idol.” 

“Watching dom do her f*ckin thing was one of the most amazing experiences of my life,” wrote Billie in the caption. “This girl is f*cking unbelievable. Will cherish you forever dom love you so much. I feel so honored to be a part of something so special, surrounded by PEOPLE so special. @donaldglover if it wasn’t for you i wouldn’t be the artist or person i am today. @ibraake & @janinenabers you rock my socks off. Truly can’t BELIEVE my reality sometimes. STREAM ‘SWARM’!! @swarmonprime 🐝🐝🐝."

“She came in and their chemistry was really wonderful,” Nabers added about Dominique and Billie. “This show, in terms of women and violence, is so empowering for me, because you see it from such a masculine standpoint usually in the history of film and TV. To subvert that with this, and with Billie, was great.”

While Billie's character does get killed by the end of the fourth episode, which means she probably won't be around for any potential future seasons, the time she does spend on screen is absolutely hypnotizing nonetheless. We're also living for Billie's BTS shots — in her March 19 photo dump, she treated fans to terrifying pics of herself as Eva, covered in blood. To see more of Eva, tune into the first season of Swarm, with all seven episodes now streaming on Prime Video.